Nickel catalyst

ABSTRACT

A formed nickel catalyst useful in fixed bed hydrogenation of fatty materials is described. The catalyst comprises from about 10% to about 50% by weight of nickel and from about 3% to about 30% by weight of at least one clay mineral binder. The catalyst may also contain from about 20% to about 60% by weight of silica and from about 1% to about 10% by weight of alumina. A process also is described for preparing such formed nickel catalyst. The use of such nickel catalyst in the hydrogenation of fatty materials such as fatty acids and esters also is described.

FIELD OF THE INVENTION

The present invention relates to formed nickel catalysts which areuseful in fixed bed hydrogenation reactions. More particularly, theinvention relates to formed nickel catalysts useful in fixed bedhydrogenation of fatty materials such as fatty acids and fatty esters.The invention also relates to the process of preparing such catalystsand to the use of such catalysts in hydrogenating fatty acids andesters.

BACKGROUND OF THE INVENTION

Supported metal catalysts are known, and their use in numerousreactions, including the hydrogenation of fatty materials, has beendescribed extensively in the literature. Supported nickel catalysts havebeen utilized in various hydrogenation processes where low IV (iodinevalue) fatty products are desired. A low IV is obtained when the productis completely or essentially completely saturated.

Fatty acid hydrogenations can be accomplished either in a slurry phasewith a powdered catalyst or in a fixed bed with a formed catalyst. Thenormal catalyst of choice is based on reduced nickel as the catalyticspecies. However, nickel, and especially any nickel oxide, nickelhydroxide, or nickel carbonate present in the catalyst tends to reactwith the fatty acids to form nickel soaps. These soaps can redeposit onthe catalyst or can be removed from the catalyst and accumulate in theslurry phase or can be carried off in the fatty acid liquid in a fixedbed reaction. As the amount of soap deposited on the catalyst increases,the activity of the catalyst decreases. In addition, any dissolvednickel soaps which are carried into the product can be deleterious tothe quality of the reduced product.

The term "supported nickel catalyst" can be defined as a catalystwherein the nickel precursor is deposited on a refractory metal oxidesupport by means of impregnation or precipitation to distribute thenickel metal as small crystallites upon the support. Examples of patentsdescribing various nickel-containing supported catalysts and their usein catalytic hydrogenation reactions include U.S. Pat. Nos. 2,812,342and 3,691,100. U.S. Pat. No. 2,812,342 discloses the hydrogenation ofstructurally modified acids using conventional catalysts such as Raneynickel catalysts and hydrogen. U.S. Pat. No. 4,317,748 describes aprocess for the preparation of supported nickel catalysts which areuseful as hydrogenation catalysts, particularly for the hydrogenation offatty materials. Examples of support materials include alumina, silica,silica gel, fumed silica, naturally occurring clays such asmontmorillonite and montmorillonite-rich minerals, carbon black,activated charcoal, etc. The catalysts described in the '748 patent aretypically free-flowing powders containing 25 % to 75 % nickel. Inparticular, the supported nickel catalysts are prepared by a processinvolving contacting a solid support material and nickel soap of amonocarboxylic acid in an inert hydrocarbon until the nickel isassociated with the support. The nickel-bearing support material is thensubjected to a sulfiding step followed by precipitation of nickel metalthereon. The use of an inert hydrocarbon is an essential feature of theprocess.

U.S. Pat. Nos. 4,174,302 and 4,3 17,748 describe catalysts which containnickel and support materials which include day. In particular, U.S. Pat.No. 4,174,302 describes a catalyst for producing cycloalkylaromaticsfrom aromatic hydrocarbons in the presence of hydrogen wherein thecatalyst consists essentially of ruthenium, nickel and a supportmaterial selected from the group consisting of active clay andsilica-alumina. The catalyst contains from about 0.01 to 0.3 weightpercent of ruthenium and from about 0.03 to 1 weight percent nickel.U.S. Pat. No. 4,317,748 is described above, and U.S. Pat. No. 4,584,140describes a process for separating fatty materials from spent supportednickel catalyst composition which may also contain non-nickel-containingclays/earths.

The preparation of nickel catalysts supported on natural silicates isdescribed by M. T. Rodrigo et al in "Applied Catalysis A: General", 88;1992 (101-114), Elsevier Science Publishers B.V., Amsterdam. FourSpanish silicates are described as useful supports:seprolite,palygorskite, bentonitc and diatomitc. The powdered catalysts describedin this article were prepared containing from 8.4 to 12 % nickel. Theactivity of the catalysts was found to be almost independent of thenature of the support, whereas differences in selectivity were ascribedto differences in the morphology of the support.

SUMMARY OF THE INVENTION

A formed nickel catalyst useful in fixed bed hydrogenation of fattymaterials is described. The catalyst comprises from about 10% to about50% by weight of nickel and from about 3% to about 30% by weight of atleast one clay mineral binder. The catalyst may also contain from about20% to about 60% by weight of silica and from about 1% to about 10% byweight of alumina. A process also is described for preparing such formednickel catalyst. The use of such nickel catalyst in the hydrogenation offatty materials such as fatty acids and esters also is described.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The formed nickel catalysts of the present invention comprise from about10% to about 50% by weight of nickel and from about 3 % to about 30% byweight of at least one clay mineral binder. In a preferred embodiment,the catalyst is a supported catalyst wherein the support comprisesrefractory metal oxides including synthetic inorganic oxides of silicon,magnesium, calcium, alumina, zinc, and mixtures thereof. Generally, therefractory metal oxide support can be alumina or silica or mixtures ofalumina and silica. Throughout this specification and claims the weightpercents of nickel are based on the total weight of the catalyst and arecalculated as the metal.

Accordingly, in one embodiment, the catalyst of the present inventionwill comprise from about 10% to about 50% by weight of nickel, fromabout 20% to about 60% of silica, from about 1% to about 10% by weightof alumina, and from about 3 % to about 30% by weight of at least oneclay mineral binder. One method by which such catalyst can be preparedis described below.

An essential component of the formed nickel catalyst of the presentinvention which is useful particularly in the fixed bed hydrogenation offatty materials is at least one clay mineral binder. The amount of claymineral incorporated into the formed catalyst is an amount which issufficient to bind the components together and maintain the shape of theformed catalyst. As noted above, the catalysts may contain from about 3% to about 30% by weight of the clay mineral binder, and in anotherembodiment, the catalysts contain from about 5 % to about 20% of claymineral binder.

Clays may be broadly defined as containing the elements silicon,aluminum, oxygen, iron, magnesium and various alkaline earth elements.They are generally hydrated silicates of aluminum, iron or magnesium andmay be crystalline or amorphous. Crystalline clays are most common andare identified and classified primarily on the basis of crystalstructure and the amount and locations of charge with respect to thebasic lattice.

The clay minerals which may be employed as binders in the formedcatalysts of the present invention may be any of the common crystallineclay minerals such as the kaolin group, the illite group, themontmorillonite or smectite group, the chlorite group, the vermiculitegroup, the sepiolite and attapulgite group, etc. Examples of the kaolingroup clays include kaolinite, dickite and nacrite which aresilicoaluminous clays and all are considered to have the chemicalformula 2SiO₂.Al₂ O₃.2H₂ O; and halloysite which is also exclusivelysilicoaluminous. Other species of the kaolin group are distinguished bythe partial replacement of aluminum by iron, magnesium, nickel ormanganese. The montmorillonite or smectite group is characterized byfinely grained, thin-layered microcrystals. The layers are not tightlybound one to another and, therefore, these clays absorb and adsorbmaterials. The most familiar of this group is montmorillonite. Relatedspecies include beidellite in which silicon is partially replaced byaluminum; nontronite in which aluminum is partially replaced by iron;saponite and stevensite in which aluminum is partially replaced bymagnesium.

Examples of clays composed predominantly of kaolinitc are china clays,kaolines, ball clays, fire clays and flint clays. Often, the terms chinaclay and kaolin are used interchangeably. Other specific examples ofuseful clays include diaspore clay which is a hydrated aluminum oxidewith an Al₂ O₃ content of about 85 % and a water content of about 15 %.Bentonites are aluminum silicate clays which are also referred to assodium smectites. In one preferred embodiment of the invention, the claywhich is utilized as a binder is selected from attapulgite, bentoniteand kaolinitc. Particularly useful attapulgite clays are available fromthe Engelhard Corporation under the general trade designation Attagel®.For example, Attagel® 50 is a dry powder having a B.E.T. surface area of150 m² /gm, and Attagel® 40 is a dry powder having a B.E.T. surface areaof about 140 m² /gm. These products typically contain about 66% SiO₂,12.2% Al₂ O₃, 11.5% MgO, 3.6% Fe₂ O₃ and 4.3% CaO.

The catalysts of the present invention also may contain small amounts ofat least one silica support material. The amount of silica supportmaterial may be varied although amounts of from about 0.5 % to about 10%are presently preferred. Various silica support materials may beutilized including diatomites such as diatomaceous earth (Kieselguhr) orperlite. Diatomites generally contain about 85-90% SiO₂ and about 3-5%of Al₂ O₃. For example, a diatomaceous earth such as Celite FC availablefrom Manville Corp. may be incorporated into the catalyst of the presentinvention.

The present invention also includes a method of preparing the formednickel catalyst of the present invention. The process comprises

(A) preparing an aqueous acidic mixture of nickel ions and a solidporous support material;

(B) combining the aqueous acidic mixture of (A) with an aqueous alkalinemixture of an alkali metal silicate and an inorganic base whereby thenickel and silicate ions are precipitated onto said support material toform a catalyst;

(C) recovering the support material containing the precipitated nickeland silicate ions;

(D) preparing a mixture of water, a clay mineral and the supportmaterial containing the precipitated nickel and silicate ions; and

(E) forming the mixture into the desired shape.

After the mixture is formed into the desired shape, the catalyst may bedried and calcined at an elevated temperature. The calcined catalyst maythen be activated by reduction with a reductant.

In one embodiment, an additional silica support material as describedabove may be added to the mixture or slurry obtained in step (B) afterthe nickel and silicate ions derived from the mixture prepared in step(A) have been precipitated into the support material but before theprecipitate containing the nickel and silicate ions is recovered in step(C). The amount of silica support material added to the mixture is anmount sufficient to provide a catalyst containing about 0.5 to about 10%of the silica support material. The silica support material in thecatalyst is to be distinguished and is different from the SiO₂ presentin the catalyst which is derived from the alkali metal silicatecontained in the aqueous alkaline mixture used in step (B).

In another embodiment the material recovered in step (C) may be washedwith water and/or dried with air blowing or at an elevated temperatureprior to proceeding with step (D).

The nickel ions which are present in the aqueous acidic mixture preparedin step (A) may be derived from any nickel source which is soluble inacidic water. For example, the nickel ions may be derived from a nickelhalide such as nickel chloride. Other nickel sources include nickelnitrate hexahydrate, nickel carbonate, nickel acetate, etc. The amountof nickel ions present in the aqueous acidic mixture used prepared instep (A) is an amount which is sufficient to provide the final catalystwith the desired nickel content which is described above as between fromabout 10% to about 50% by weight. The acidity of the aqueous mixture iscontrolled by the amount of acid added to the mixture. Generally, amineral acid such as hydrochloric acid or nitric acid is utilized. ThepH of the aqueous acidic mixture used in step (A) generally is in therange of from less than 1 to about 5. The aqueous acidic mixture used instep (A) is generally prepared by adding the nickel compound to waterfollowed by the addition of the inorganic acid to acidify the mixture tothe desired pH. This mixture generally is heated to a temperature suchas from about 30° C. to about 60° C., and the support material is thenadded. Following the addition of the support material, the mixture isheated to about 75° C. or 80° C.

The solid porous support material incorporated into the aqueous mixtureused in step (A) may be any refractory metal oxide support such asalumina, silica, zinc oxide, zirconium oxide and mixtures thereof.Alumina is a preferred support material of the present invention.Specific examples of useful commercially available aluminas includecertain members of the Versal family of aluminas available from KaiserAluminum and Chemical Corporation; and Boehmite aluminas such as Catapalaluminas sold by Vista Chemical Company and Pural (Boehmite) availablefrom Condea Chemie. Mixtures of these aluminas can also be used as thesupport material for the catalyst of the present invention. The amountof support material is an mount which is sufficient to provide the finalcatalyst with from about 1% to about 10% by weight of the supportmaterial.

The second aqueous mixture which is utilized in the process of thepresent invention is an aqueous alkaline mixture of an alkali metalsilicate and an inorganic base. Alkali metal silicates such as sodium orpotassium silicates may be utilized to prepare the mixture and theinorganic base is preferably an alkali metal base such as sodiumhydroxide, potassium hydroxide or a precursor such as sodium oxide,potassium oxide, etc. The aqueous alkaline mixture generally is preparedby adding the inorganic base or base precursor to water and thereafteradding the alkali metal silicate.

The aqueous acidic mixture containing the nickel ions and the supportmaterial, and the aqueous alkaline mixture containing the alkali metalsilicate are combined whereupon the nickel and silicate ions areprecipitated onto the support material. Although the two mixtures may becombined in any manner, it is generally preferred that the aqueousalkaline mixture is added to the aqueous acidic mixture over a period oftime such as from about 0.5 to about 2 hours with stirring whilemaintaining the temperature at about 70°-80° C. When the addition of theaqueous alkaline mixture is completed, the pH of the combined mixture isadjusted to about 8 to 9, generally with an aqueous solution of sodiumor potassium hydroxide.

The support material containing nickel and silicate ions is thenrecovered from the slurry by any technique known to those skilled in theart including filtration, settling, centrifuging, etc. The solids thusrecovered may be washed with water and dried by heating to temperaturesup to about 100°-110° C. or higher for periods of from about 1 to about8 hours.

The catalyst is prepared from the support material containing nickel andsilicate ions by preparing a formable mixture of water, clay mineral andthe precipitated material containing nickel and silicate ions, andthereafter forming the mixture into a catalyst having the desired shape.Generally, this mixture is prepared by adding the clay to theprecipitated, supported material and mixing to obtain an intimatemixture. Water is then added to the mixture, and the amount of wateradded should be an amount which is sufficient to form a mix which issuitable for the forming process, for example, an extrudable mix. Theamount of clay mineral included in the mixture is an amount which willprovide the catalyst with from about 5% to about 25% by weight of theclay binder. Thus, the amount of clay mineral contained in the formable(e.g., extrudable mixture) will range from about 5% to about 20% or even30% by weight based on the weight of the precipitated, supportedmaterial containing the nickel and silica.

The formed nickel catalyst of the present invention may be prepared inany desired shape by a variety of forming procedures includingextrusion, briquetting, tabletting, etc. Thus, the shape of the catalystcan be in the form of extruded, briquetted or tabletted cylinders,polylobal extrusions, spheres, rings, hollow core cylinders, or anyother appropriate geometric shape. The different forming techniques mayrequire mixes with different moisture contents as will be readilyapparent to those skilled in the art.

In one preferred embodiment, the formed catalysts of the invention areprepared by extruding the above-described mixtures to form an extrudate.The size and shape of the extrudate can be varied over a wide rangealthough the size generally is from about 1/32-inch to about 3/8-inch indiameter.

The dried catalyst may be calcined and thereafter reduced or reduceddirectly in hydrogen. Generally, the dried catalyst is calcined byheating with flowing air or inert gas to a temperature of from about110° C. to about 600° C. or higher, preferably from about 350° C. toabout 500° C. The time and temperature of the calcination should besufficient to decompose the metal salts, convert the metals to metaloxides and to fix the metal oxides in this support. Any type ofcalciner, such as a rotary kiln, tunnel kiln, vertical calciner, etc.,can be used so long as the metals are converted to metal oxides.

The formed and calcined catalyst described above can be activated byreduction at an elevated temperature in the presence of a gaseousreductant such as hydrogen. At least a potion of the nickel in thecatalyst should be reduced. The reduced catalyst can then be stabilizedby depositing a mono-molecular layer of carbon dioxide on the catalystto prevent spontaneous oxidation of the highly active nickel when thecatalyst is exposed to the air. In one embodiment, the calcined catalystof the present invention is reduced with hydrogen at a temperature ofabout 75°-500° C., more often 400°-500° C. and thereafter cooled toabout 50° C. and stabilized by contacting the reduced catalyst withcarbon dioxide.

The following examples illustrate the catalysts of the present inventionand their method of preparation. Unless otherwise indicated, all partsand percentages are by weight, temperatures are in degrees Centigrade,and pressures are at or near atmospheric pressure.

EXAMPLE 1

A mixture of 27.474 Kg of an aqueous nickel chloride solution containing13.42% nickel, 282 grams of concentrated nitric acid and 13.4 gallons ofwater is prepared in a reactor vessel, and 694 grams of Pural aluminaare added. The temperature of the mixture is raised to about 75° C.

In a separate vessel, a mixture of 43 gallons of water and 7.693 Kg of a50% aqueous sodium hydroxide solution is prepared. To this mixture thereare added 12.388 Kg of a sodium silicate solution containing 28.9% SiO₂.The SiO₂ /Na₂ O ratio in the sodium silicate is about 3.25:1. Themixture in the second vessel is then added slowly with stirring to themixture in the reaction vessel over a period of about one hour whilemaintaining the temperature at about 75° C. When all of the secondsolution has been added, the pH of the mixture in the reaction vessel isadjusted to between about 8 and 9 with a 50% aqueous sodium hydroxidesolution. The mixture in the reaction vessel is heated to 94°-97° C. andmaintained at this temperature for one hour. The reaction mixture isthen quenched with 30 gallons of water, and 1.239 Kg of Celite F.C. areadded to the reactor and the slurry is mixed for about 10 minutes. Theslurry is then pumped into a filter press, faltered, and the residue iswashed overnight. The washed residue is then blown with air for 30 to 45minutes, removed from the press and dried at 105° C. for 2 to 6 hours.The dried residue is then milled to a powder.

To a mixer there are charged 309.09 Kg of the dried solid prepared aboveand 37.27 Kg of Attagel 50. The mixture is mixed for 2 to 5 minuteswhereupon 186.36 Kg of water are added over a period of 5 to 8 minuteswhile stirring. This mixture is stirred for an additional 20 minutes andthen extruded through a 0.070-inch cylindrical dye. The extrudate isdried at about 150° C. (300° F.). The dried extrudate is then calcinedat a temperature of 390° C. for one hour, reduced with hydrogen for 2hours at about 450° C. and then for an additional period of time as thecatalyst is cooled to 50° C. and then stabilized with carbon dioxide.Analysis of the catalyst thus obtained indicates a nickel content ofabout 32%, a nickel crystallite size of about 85Å, and a crush strengthof about 12.3 pounds per 3/16-inch.

EXAMPLE 2

The general procedure of Example 1 is repeated except that only 18.64 Kgof Attagel 50 are used. The catalyst prepared in this manner contains33.7% nickel, has a nickel crystallite size of 75Å and a crushingstrength of 9.5 pounds per 3/16-inch.

EXAMPLE 3

The procedure of Example 1 is repeated except that the Attagel 50 isreplaced by the 37.27 Kg of Bentonite (200 mesh green bond SJ fromAshland Chemical Co.). The catalyst prepared in this manner contains31.4% nickel, has a nickel crystallite size of 70Å and a crush strengthof 7.0 pounds per 3/16-inch.

EXAMPLE 4

The procedure of Example 1 is repeated except that the Attagel isreplaced by 37.27 Kg of kaolin (Kaolin ASP-400 available from EngelhardCorporation). The catalyst prepared in this manner contains 32.6%nickel, has a nickel crystallite size of 70Å and a crush strength of12.8 pounds per 3/16-inch.

CONTROL EXAMPLE

The procedure of Example 1 is repeated except that the Attagel isreplaced by 37.27 Kg of Catapal® Boehmite alumina available from VistaChemical Co. The catalyst prepared in this manner contains 32.2% nickel,has a crystallite size of 90Å and a crush strength of 12.9 pounds per3/16-inch. In this case, an acid is added to peptize the alumina.

The formed nickel catalysts of the present invention are usefulparticularly in fixed bed hydrogenation reactions, and moreparticularly, in the hydrogenation of fatty materials such as fats andoils in components thereof, particularly unsaturated fatty acids andfatty acid esters, such as oleic acid, linoleic acid, tall oil acid,methyl oleate, methyl linoleate, ethyl oleate, etc. The fatty materialsare hydrogenated by contacting the fatty materials with hydrogen and acatalyst of the present invention under catalytic hydrogenationconditions. Preferably, the hydrogenation is accomplished in a fixed bedreactor system.

As mentioned above, one of the difficulties of using nickel-containingsupported catalysts, particularly in a fixed bed hydrogenation reaction,is that the nickel present in the catalyst tends to react with fattyacids and fatty esters to form nickel soaps, and these soaps can bedeposited on the catalyst or they can accumulate in the reduced fattyacid product. As a result, the activity of the catalyst is diminished,and the dissolved nickel soaps have a deleterious effect on the qualityof the hydrogenated fatty acid obtained. However, it has now beenobserved that when a fixed bed hydrogenation is carried out on fattymaterials utilizing the catalyst of the present invention, the catalystis very effective in producing hydrogenated fatty acids, and there is asignificant reduction in the amount of nickel contained in the productwhen compared to a similar catalyst using other binders such as alumina.In addition, the amount of aluminum contained in the fatty oil productas a result of the dissolution of aluminum from the binder issignificantly less than the amount of aluminum present in the productobtained using a control catalyst which is identical to the catalyst ofthe present invention except an equivalent amount of Catapal alumina isused as the binder. It is obviously undesirable to obtain hydrogenatedfatty acids which contain significant amounts of nickel and/or aluminum.

The ability of the catalyst of the present invention to reduce fattymaterials and to produce hydrogenated fatty materials containing reducedamounts of nickel and aluminum is demonstrated by comparing the resultsobtained with the catalysts of the invention as described in Examples 1,3 and 4 with the results obtained with the Control Catalyst describedabove which was prepared by the same procedure utilized to prepare thecatalyst of the present invention except that the clay component wasreplaced by an equivalent amount of alumina. The procedure for thisevaluation involved loading about 30 grams of the formed, reduced andstabilized nickel catalyst into a reactor tube and then allowing ableached tallow fatty acid having an iodine value of 51 and hydrogen toflow from above through the formed catalyst. The product is collectedfrom the other end of the reactor tube and analyzed for unsaturation(iodine value), ppm of nickel, and ppm of aluminum. Samples are takenevery 15 minutes over a test period of 3 hours during which time thecatalytic activity is reasonably constant. The results of thisevaluation are summarized in the following table.

                  TABLE                                                           ______________________________________                                        Hydrogenation Results                                                         Catalyst of                                                                             Iodine        Ni      Al                                            Example   Value         (ppm)   (ppm)                                         ______________________________________                                        1         34.1          8       <10                                           3         36.0          3       <10                                           4         29.8          5        20                                           Control   38.7          120      120                                          ______________________________________                                    

As can be seen from the above results, the catalysts of the presentinvention which contain clay are more effective in the hydrogenation ofthe fatty acid (lower iodine value), and the product obtained containssignificantly less nickel and aluminum contamination than the productobtained with the Control Catalyst. These results indicate that thealumina and active nickel contained in the catalyst of the presentinvention remain in the catalyst, and the catalyst retains its integrityby retaining the binder and remains effective for a longer period oftime than the control catalyst because the nickel remains in thecatalyst.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

I claim:
 1. A formed nickel catalyst supported by a refractory metaloxide support material, said formed supported catalyst being useful infixed bed hydrogenation of fatty materials and comprising from about 10%to about 50% by weight of nickel and from about 3 to about 30% by weightof at least one clay mineral binder.
 2. The catalyst of claim 1 havingan SiO₂ content of from about 20% to about 60% by weight.
 3. Thecatalyst of claim 1 wherein the refractory metal oxide support materialcomprises alumina present in the amount from about 1% to about 10% byweight of the catalyst.
 4. The catalyst of claim 1 containing from about25% to about by weight of nickel.
 5. The catalyst of claim 1 wherein theclay mineral is a montmorillonite, kaolinitc or attapulgite clay.
 6. Thecatalyst of claim 1 containing from about 5% to about 20% by weight ofthe clay binder.
 7. A formed nickel catalyst comprising (i) nickelsupported on a refractory metal oxide support material and (ii) at leastone clay mineral binder, said formed supported catalyst being useful infixed bed hydrogenation of fatty acids and esters and comprising fromabout 25% to about 45% by weight of nickel, from about 25% to about 45%SiO₂, from about 1% to about 10% by weight of Al₂ O₃.
 8. The catalyst ofclaim 7 also containing from about 0.5% to about 10% by weight of atleast one silica support material.
 9. The catalyst of claim 8 whereinthe silica support material is diatomaceous earth.
 10. A process forpreparing a supported and formed catalyst which comprises(A) preparingan aqueous acidic mixture of nickel ions and a solid refractory metaloxide support material; (B) combining the aqueous acidic mixture of (A)with an aqueous alkaline mixture of an alkali metal silicate and aninorganic base whereby the nickel and silicate ions are precipitatedonto said support material; (C) recovering the support materialcontaining the precipitated nickel and silicate ions; (D) preparing amixture of water, a clay mineral and containing the precipitated nickeland silicate ions; and (E) forming the mixture into a catalyst of thedesired shape.
 11. The process of claim 10 wherein the catalyst formedin step (E) is dried and calcined at a temperature of from about110°-600° C.
 12. The process of claim 10 wherein the support material inthe mixture used in step (A) is alumina, silica or a mixture of aluminaand silica.
 13. The process of claim 10 wherein the inorganic base in(B) is an alkali metal hydroxide.
 14. The process of claim 10 whereinthe clay mineral is a montmorillonite, kaolinite or attapulgite clay.15. The process of claim 10 wherein diatomaceous earth is added to themixture obtained in step (B) prior to recovery of the catalyst in step(C) .
 16. The process of claim 10 wherein the aqueous mixture of (A) iscombined with the aqueous alkaline mixture of (B) by the addition of theaqueous alkaline mixture to the aqueous acidic mixture.
 17. The processof claim 11 which additionally includes the step of reducing at least aportion of the nickel in said catalyst at an elevated temperature in thepresence of a reductant.
 18. The process of claim 17 wherein thereductant is a gaseous reductant.
 19. The process of claim 18 whereinthe reductant is hydrogen.
 20. The process of claim 17 wherein thereduced catalyst is stabilized by contact with carbon dioxide.